While picture and sound synchronization was realized a long time ago in the motion pictures industry, a practical system for achieving the same result was not available in the projectable transparencies field until the inventor of the present invention taught simple and efficient methods for integrating sound with slides. He did so in inventions such as those he disclosed in U.S. Pat. Nos. 3,122,053 3,122,054 3,282,154 3,302,520 3,480,356 3,644,032 3,717,407 3,730,618 3,825,332, and others.
Methods for adding sound to images, or printed pages, have been proposed since the turn of the century and usually consist of linear or spiral sound tracks disposed on the same, or the opposite pages of sheets carrying visual information. The problem is that each such audiovisual sheet must be separately inserted in the appropriate apparatus and this is not only impractical, but the sheets may easily be misled, intermixed and generally their sequence lost.
The problem is not much different from that encountered in simple photography or, for that matter, in the field of printed intelligence. Printed sheets, are bound in volumes and photographs are mounted in albums for convenience and also to preserve the necessary sequence.
The instant invention solves these problems by disclosing simple and convenient audiovisual books and audiovisual albums as well as novel audiovisual sheets and apparatuses employed therewith.